Pen



FIG. 1 is a top left side isometric view of a pen in accordance with the new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a front elevational view thereof.

The broken lines shown in FIGS. 1-7 are for the purpose of illustrating portions of the pen that form no part of the claimed design. 

CLAIM The ornamental design for a pen, as shown and described. 